| Biofilms are bacterial cells encased in an extracellular matrix composed of polymeric substances. Biofilm growth is a developmental process, starting with cells attaching to a substratum, progressing into a mature biofilm, and culminating with the dispersion response, where cells detach from the biofilm. In this final step, the extracellular matrix encasement must be broken down in order for the cells to escape the biofilm and return to their planktonic state. Compared to other stages of biofilm development, the final stage of dispersion is not well understood and the mechanism of the response is not fully characterized. The hypothesis of this project was that following dispersion induction, P. aeruginosa cells released proteins responsible for the degradation of extracellular matrix macromolecules. The cell-free supernatant liquids of dispersion-induced cells were tested for the presence of macromolecule-degrading enzymes and it was shown that following dispersion, the cells released enzymes capable of degrading protein, DNA, and polysaccharides. The extracellular protein profiles of dispersion-induced and uninduced cells were examined with two-dimensional PAGE. Proteins unique to the dispersion response were identified by mass spectroscopy analysis. Thirty-five confirmed protein identifications were obtained. |
